HttpClient调用

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文章目录

• ​​一、HttpClient调用​​

• ​​1、get不带参数调用​​
• ​​2、get带参数调用​​
• ​​3、post不带参数调用​​
• ​​4、post带参数调用​​

• ​​二、HttpClient调用工具类​​
• ​​三、总结​​

一、HttpClient调用

1、get不带参数调用

package com.xiaoqi.httpclient;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.junit.Test;

public class HttpClientTest {

    @Test
    public void doGet() throws Exception{//不带参数的http请求
        //创建一个httpclient对象
        CloseableHttpClient http = HttpClients.createDefault();
        //创建一个Get对象
        HttpGet get = new HttpGet("http://www.baidu.com");
        //执行httpclient调用
        CloseableHttpResponse response = http.execute(get);
        //获取状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println("状态："+ code);
        //获取内容
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity,"utf-8");
        System.out.println("获取的内容："+ string);
        //关闭httpclient
        response.close();
    }

2、get带参数调用

@Test
    public void doGetWith() throws Exception{//带参数的http请求
        //创建一个httpclient对象
        CloseableHttpClient http = HttpClients.createDefault();
        //创建一个URI对象并传入地址
        URIBuilder uri= new URIBuilder("https://www.baidu.com/s");
        //给URI对象添加参数
        uri.addParameter("wd", "程序员");
        //创建一个http对象并传入URI对象
        HttpGet httpGet = new HttpGet(uri.build());
        //执行http请求
        CloseableHttpResponse response = http.execute(httpGet);
        //获取状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println("状态码："+code);
        //获取返回值
        HttpEntity entity = response.getEntity();
        String string = EntityUtils.toString(entity);
        System.out.println("返回值："+string);
    }
}

3、post不带参数调用

@Test
    public void doPost() throws Exception{
        //创建一个httpclient对象
        CloseableHttpClient http = HttpClients.createDefault();
        //创建一个httppost对象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");
        //执行httpclient请求
        CloseableHttpResponse response = http.execute(post);
        //获取返回状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println("状态码："+code);
        //获取返回值
        String string = EntityUtils.toString(response.getEntity());
        System.out.println("返回值："+string);
    }

4、post带参数调用

@Test
    public void postWith() throws Exception{//post请求带参数
        //创建一个httpclient对象
        CloseableHttpClient http = HttpClients.createDefault();
        //创建一个httppost对象
        HttpPost post = new HttpPost("http://localhost:8082/httpclient/post2.html");
        //创建一个post表单
        List<NameValuePair> list = new ArrayList<NameValuePair>();
        //存放参数
        list.add(new BasicNameValuePair("name", "张三"));
        list.add(new BasicNameValuePair("password", "123"));
        
        //包装一个entity对象
        StringEntity entity = new UrlEncodedFormEntity(list);
        //将参数放入post请求中
        post.setEntity(entity);
        //执行http请求
        CloseableHttpResponse response = http.execute(post);
        //获取状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println("状态码："+code);
        //获取返回值
        String string = EntityUtils.toString(response.getEntity());
        System.out.println("返回值："+string);
    }

二、HttpClient调用工具类

package com.taotao.common.utils;

import java.io.IOException;

import java.net.URI;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import org.apache.http.NameValuePair;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.CloseableHttpResponse;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.client.utils.URIBuilder;

import org.apache.http.entity.ContentType;

import org.apache.http.entity.StringEntity;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.message.BasicNameValuePair;

import org.apache.http.util.EntityUtils;

public class HttpClientUtil {

    public static String doGet(String url, Map<String, String> param) {

        // 创建Httpclient对象

        CloseableHttpClient httpclient = HttpClients.createDefault();

        String resultString = "";

        CloseableHttpResponse response = null;

        try {

            // 创建uri

            URIBuilder builder = new URIBuilder(url);

            if (param != null) {

                for (String key : param.keySet()) {

                    builder.addParameter(key, param.get(key));

                }

            }

            URI uri = builder.build();

            // 创建http GET请求

            HttpGet httpGet = new HttpGet(uri);

            // 执行请求

            response = httpclient.execute(httpGet);

            // 判断返回状态是否为200

            if (response.getStatusLine().getStatusCode() == 200) {

                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");

            }

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                if (response != null) {

                    response.close();

                }

                httpclient.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

        return resultString;

    }

    public static String doGet(String url) {

        return doGet(url, null);

    }

    public static String doPost(String url, Map<String, String> param) {

        // 创建Httpclient对象

        CloseableHttpClient httpClient = HttpClients.createDefault();

        CloseableHttpResponse response = null;

        String resultString = "";

        try {

            // 创建Http Post请求

            HttpPost httpPost = new HttpPost(url);

            // 创建参数列表

            if (param != null) {

                List<NameValuePair> paramList = new ArrayList<>();

                for (String key : param.keySet()) {

                    paramList.add(new BasicNameValuePair(key, param.get(key)));

                }

                // 模拟表单

                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);

                httpPost.setEntity(entity);

            }

            // 执行http请求

            response = httpClient.execute(httpPost);

            resultString = EntityUtils.toString(response.getEntity(), "utf-8");

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                response.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

        return resultString;

    }

    public static String doPost(String url) {

        return doPost(url, null);

    }

    public static String doPostJson(String url, String json) {

        // 创建Httpclient对象

        CloseableHttpClient httpClient = HttpClients.createDefault();

        CloseableHttpResponse response = null;

        String resultString = "";

        try {

            // 创建Http Post请求

            HttpPost httpPost = new HttpPost(url);

            // 创建请求内容

            StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);

            httpPost.setEntity(entity);

            // 执行http请求

            response = httpClient.execute(httpPost);

            resultString = EntityUtils.toString(response.getEntity(), "utf-8");

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                response.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

        return resultString;

    }

}

三、总结

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